This invention relates to improvements in a magnetic recording medium for use in the form of a video tape, computer tape, high performance sound recording tape, multicoat tape, magnetic disk, floppy disk, magnetic card, or the like.
Magnetic recording materials for those applications generally use a thermosetting binder, and a three-dimensional network structure is formed by a chemical reaction of a cross-linking agent, such as a polyisocyanate-radical-containing compound, with reactive functional groups, such as hydroxyl, amino, or the like, in the binder. The formation of the structure is intended to prevent the magnetic recording layer from coming off and to improve the durability, running properties, and environmental reliability of those magnetic media. Also, the conventional media employ a silane coupling agent for the purpose of organic or inorganic complexing or compounding. With a coupling agent of the kind, however, it is still impossible to obtain satisfactory dispersion of an inorganic solid powder in magnetic pigments which contain such ferromagnetic metals as Fe, Co, and Ni. As a consequence, the bonds between the magnetic material and the binder and between the magnetic recording layer and the substrate are insufficient and weak, causing a progressive and rapidly intensified tendency of dropouts from the both edges inwardly of the tape as it runs past the record or play head.